Transport device

ABSTRACT

The present invention relates to a pallet comprising first and second base parts (A 1  and B 1 ), each folded from pieces of corrugated, waterproof fiber material, for instance paper. Rectangular pieces (A, B) are cut from rolls of fiber material and the two base parts are made by notching and folding the pieces according to separate sequences. The first base part (A 1 ) is put into the second base part (B 1 ) and beams ( 31 ) on the second base part are folded in under the first base part and constitutes the feet of the pallet. The beams have longitudinal, v-shaped inner stiffeners ( 21, 22 ). All surfaces and points on the two base parts in contact with each other are glued and all open edges on ends and openings are provided with waterproof layers.

BACKGROUND OF THE INVENTION

The present invention relates to a pallet for transport and handling ofgoods with a forklift truck and, particularly a pallet comprising atleast two base parts made of corrugated, waterproof fiber material.

The pallet is an important aid in modern transports and is made in manydifferent ways and designs. A traditional type of pallet is made ofwood, which is heavy and contributes to increased transport weight andthereby increased transport costs. Many other pallet designs indifferent materials, for instance plastic or fiber material has beendeveloped. Several solutions disclose pallets in which more or lesscomplicated details of fiber material, preferably paper, corrugated orplane, are assembled to achieve the desired form and strength.

The pallets according to the Swedish patent applications 450 481, 450482 and 459 251 disclose designs with three base parts assembled with anumber of transverse elements with a circular or rectangular crosssection. The elements are inserted through openings of correspondingshape in the three base parts so the pallet can be lifted with a forkfrom all sides. The designs are characterized by a large number ofdetails which have to be assembled and by an extensive amount of holesthat have to be made in the base parts.

U.S. Pat. No. 3,113,532 discloses a pallet design with one base partfolded to a system of channels provided with openings permitting accessfrom all sides. A number of supporting and stiffening elements are fitin between the channels. This pallet also has many details and requiresmany different operations to be assembled.

U.S. Pat. No. 5,285,731 discloses a pallet with a complicated foldingpattern and many details. The pallet is only accessible with a fork fromtwo opposite sides.

U.S. Pat. No. 5,911,834 discloses a pallet comprising a first base partwith a great number of punched parties forming inner supports andproviding openings for the fork legs. A first base part is enclosed by asecond base part keeping the first base part together. The design iscomplicated and requires many punching and folding operations. A seconddesign has one further element in the center of the first base partmaking the design even more detailed and complicated to manufacture andassemble.

U.S. Pat. No. 3,952,672 discloses a pallet that comprises a first basepart folded around a second base part. This design also has many puncheddetails, which have to be folded in different directions to createsupports and channels.

All designs, except for the first three cited, disclose low palletheight which in fact requires less space but at the same time offers alimited bending strength which is unfavorable for their main purpose,namely to carry load. Common to all pallets cited is that cutting andpunching give a great wastage, as the basic material cannot beeffectively utilized. Many details and complicated procedures both atmanufacturing of details and assembling contribute to high productioncosts. Since the life of the pallets is limited due to the type ofmaterial, it is important that they are simple to produce and cheap.

SUMMARY OF THE INVENTION

The object of present invention is to eliminate the disadvantages of thepallets described above and achieve a pallet whose base parts can bemade from rolls of corrugated fiber material by just cutting pieces ofappropriate length, completely without wastage, fold them to therequired shape and assemble them to a pallet accessible from all sidesand having a large bending and shearing strength in all directions.

A pallet according to the invention having the characteristics stated inclaim 1 and the subsequent claims achieves this object.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the invention will now be described withreference to the enclosed drawings on which:

FIG. 1 shows a plane view of the upper side of a first piece of fibermaterial;

FIG. 2 shows a side view of a first base part, upside down;

FIG. 3 shows a plane view of the upper side of a second piece of fibermaterial;

FIG. 4 shows a side view of a second base part in a first stage, upsidedown;

FIG. 5 shows a side view of a second base part joined to the first basepart, upside down;

FIG. 6 shows a perspective view of a pallet from below;

FIG. 7 shows a perspective view of a pallet from above.

FIG. 1 is shown the upper side of a first rectangular piece A ofpreferably corrugated, waterproof fiber material having fiber layers onboth sides and the corrugation lengthwise. It is cut to a length, whichwhen folded according to the side view of FIG. 2, forms a first basepart A1 with a length corresponding to a pallet of requested size. Sincethe rectangular piece A is symmetrical to a center line the samenumbering is used on both sides of the center line.

The rectangular piece A is prepared by embossing (solid line means fromabove and dashed line from underneath) in order to obtain foldingnotches on the side towards which the material is to be folded. Thematerial is divided into parts 1-14, which after folding give the basepart A1 length and width of the pallet in question and a height which inthe preferred embodiment corresponds to preferably half the height ofthe complete pallet.

The folding sequence is described in the table below:

Folding angle Part Folding direction in degrees 1 upwards 90 2 upwards90 3 upwards 90 4 downwards 180  5 upwards 90 6 upwards 90 7 downwards180  8 upwards 90 9 upwards 90 10  downwards 90 11  downwards 90 12 upwards 90 13  upwards 90 14  downwards 180 

After the piece A is folded according to this sequence, from the shortsides and inwards, the surfaces between the parts 4 and 5, 7 and 8 and14 and 14 are glued together. The piece A has now taken the shape of afirst base part A1 for a pallet shown upside down in a side view in FIG.2. The folding operations have formed a number of channels, three ateach end and two in the middle. Between the outer and middle channelstwo spaces 15 are formed. These spaces have width, height and distanceto each other permitting a fork of a fork lift truck to be positionedinto them.

In FIG. 3 is shown a second rectangular piece B made from the samematerial as the piece A and with the corrugation in the longitudinaldirection. It is cut to a length that forms a second base part B1 whenfolded according to the folding pattern shown in FIG. 3. Thisrectangular piece is also symmetric to a center line and for whichreason the numbers are the same on both sides of the center line.

The second rectangular piece is treated by embossing in the same way asthe first piece to achieve folding notches on the side towards which thematerial is to be folded. The second piece is divided into parts 21-28as shown in FIG. 3.

In the parts 27, along the edges closest to the center line andsymmetric to the longitudinal center line, openings 29 and 30 are made.The openings have width, height and distance to each other permitting afork of a fork lift truck to be positioned into them, i. e., they havethe same shape and dimensions as the spaces in the first base part A1.

The folding sequence is described in the table below:

Folding angle Part Folding direction in degrees 21 downwards ca 90 22upwards ca 135 23 upwards 90 24 downwards 90 25 upwards 90 26 upwards 90

After the piece B has been folded according to the above sequence, up tothe parts 23, from the short sides and inwards, the surfaces between theparts 23 and 27 are glued together. After the folding sequence has beencarried out, the piece B has got the shape according to FIG. 4, whichshows a side view of the second base part B1 upside down, where the part28 is the upper side of the pallet.

The under side of part 28 and the parts 24 and 27 of the second basepart B1 are covered with glue. The first base part A1 is then placedwith the parts 1 and 11 and the points formed by the parts 4, 5 and 7, 8against the part 28, with the two longitudinal beams 31 outside the longsides of the first base part A1 that the edges and the center lines ofthe base parts overlap, as shown in FIG. 4. The parts 27 are folded 90°upwards until they contact the edges of the channel openings in the longsides of the first base part A1 and the parts 24 will contact theunderside of the parts 3, 6, 9 and 13 of the first base part A1.

The two base parts are fixed in this position until the glue hashardened. The result is a pallet shown in the perspective views in FIGS.6 and 7.

The open end surfaces at the short sides are provided with a waterprotecting layer to prevent water to get in through the open cutsurfaces in the two longitudinal beams 31 underneath the pallet and inthe part 28. The cut surfaces of the openings 29 and 30 and thecorresponding surfaces on the other side are also protected.

The pallet according to the invention is produced with a minimum ofmaterial wastage. The basic material is preferably a roll of corrugatedpaper with widths corresponding to the widths of pieces A and B,respectively. The pattern for each piece of material is the simplestpossible and the number of operations by machine and hand are few andsimple.

The longitudinal beams 31 of the pallet has a high strength regardingbending and shearing forces due to the interior stiffeners formed by thefirst and second parts 21 and 22. These parts also contribute to a highdegree of impact resistance in the lower, edges of the beams, which isvery important, as they are the most vulnerable parts of the pallet. Theway the two base parts A1 and B1 are assembled provides the upper sideof the pallet and thereby the top of the two fork channels for long sidelifts, formed by the spaces 15 in the first base part A1, with twolayers of corrugated material.

A pallet of the preferred embodiment described above has passedextensive handling and load tests without any remarks.

The weight of the pallet is low, only approximately 5.5 kg, while apallet made of wood in dry condition weighs approximately 23 kg.

The pallet according to the invention is preferably intended to satisfythe requirements of European standard but can, within the scope of theinvention, be made to satisfy other standards regarding shape, size andhandling.

What is claimed is:
 1. A pallet comprising at least two base parts madeof corrugated fiber sheets, wherein a first rectangular piece, having alongitudinal corrugated layer with opposed long sides and short sidesbetween an upper side and an under side and a width that after a firstfolding sequence forms a first base part symmetrical to a center line,is divided into 14 parts by fold lines of which the three first are madefrom the upper side, the fourth from the under side, the fifth and sixthfrom the upper side, the seventh from the under side, the eighth andninth from the upper side, the tenth and eleventh from the under side,the twelfth and thirteenth from the upper side and the fourteenth fromthe under side, whereby the first piece, when folded at the fold lines,from the short sides towards a first center line, forms the first basepart with three adjacent channels with rectangular cross-section at eachend and a height preferably equal to half the height of the pallet andtwo adjacent channels with the same rectangular cross-section on eachside of the first center line and spaces between the three adjacentchannels and the two adjacent channels permit positioning of a fork on afork lift truck, wherein a second rectangular piece having alongitudinal corrugated layer between an upper side and an under sideand a width equal to the length of the pallet and after a second foldingsequence forms a second base part, symmetrical to a second center line,said second rectangular piece is divided into 7 parts by fold lines ofwhich the first fold lines are outer fold lines made in the under sideand the other fold lines are in the upper side and wherein a distancebetween the two inner most pair of fold lines on either side of thesecond center line is equal to the width of the pallet and havingrectangular openings with width, height and length and a distance toeach other equal to the spaces in the first base part, whereby thesecond piece, when folded along the fold lines, from the ends towardsthe center, forms the second base part having longitudinal beams at eachend with interior stiffeners formed by first and second parts, whereinthe first base part is laid into the second base part with thelongitudinal beams under the long sides of the first base part and theinner most part of the second piece outside the long sides so that theedges coincide, and the rectangular openings coincide with the spaces inthe first base part and the longitudinal beams are in contact with theunder sides of the channels of the first base part and support thepallet, and contacting surfaces and contacting points within and betweenthe base parts are glued.
 2. A pallet according to claim 1, wherein thefirst base part comprises two symmetrical parts made by folding thefourteen parts and the fourteenth parts are glued together.
 3. A palletaccording to claim 1, wherein the fiber sheets and all open cut surfacesare coated with waterproofing layers.